The role of podocytes in the early detection of pre-eclampsia

Abstract

Introduction Pre-eclampsia is a significant cause of maternal and neonatal mortality and morbidity in resource constrained countries. Because the exact aetiology is unknown, treatment of preeclampsia is empiric. Therefore, researchers have been investigating biomarkers for early detection of the syndrome to take steps to prevent complications. The kidney is reported to be affected by the preeclamptic process before clinical signs appear. Podocytes have been suggested as possible markers for this syndrome. However there is debate as to which is the best way to measure the amount of podocyturia. Objective To determine the best method to estimate podocyturia as a biomarker. Methods Midstream urine specimens were collected from 18 normotensive healthy primigravidae at their first antenatal visit. Urinary podocyte immunolabelling was performed by two techniques viz., culture and cytospin on urine from normotensive and clinically healthy pregnant women. Main outcome measured Are the podocyte specific proteins, podocalyxin, podocin, nephrin and synaptopodin able to detect pre-eclampsia prior to the development of clinical signs as measured by two separate techniques. Results The results suggest that the expression of podocyte specific proteins, podocalyxin, podocin, nephrin and synaptopodin, is identifiable and quantifiable from midstream urine in healthy normotensive pregnant women. Cytospin was more efficient in determining the podocyte specific protein expression levels and podocalyxin was the most sensitive marker, with a Kappa coefficient of 0.23. Conclusions These findings suggest that immuno-expression of podocyturia are best detected by the cytospin method.